1. Field of the Invention
This invention relates in general to back (spinal) braces and in particular to such back braces as employ strap means for applying tension between an anterior frame and a back pad.
2. Description of the Prior Art
Various types of back braces are known which have as their fundamental characteristic the application of tension between an anterior frame and a back pad. The anterior frame of such braces is configured to be applied to the anterior thoracic area of a person and is padded where it contacts the body. The back pad is connected to the left and right sides of the anterior frame by one or more straps which are adjustible to provide a suitable degree of tension, whereby the back pad applied pressure to a selected area of the spine for support and relief of pain.
An example of a prior back brace of the type discussed above is shown in U.S. Pat. No. 4,173,973, issued to Hendricks on Nov. 13, 1979. Hendricks shows a cruciform shaped anterior frame having pads mounted at the ends of each of the arms, including sternal, pubic and two side pads, with the pads being shaped to conform to the area of the body which they contact. The length of each arm is adjustible to accomodate different sized persons.
The Hendricks back pad has left and right wings having corresponding left and right slots therethrough. A right strap is reeved through the right slot of the back pad with both ends of the strap being connected to the right side pad by means of apertures in the strap which fit over a stud on the side pad. Multiple apertures spaced lengthwise on the strap permit adjustment of the length of the strap. A similar left strap is provided for connecting the left slot of the back pad to the left side pad.
A difficulty with a Hendricks type strap arrangement is that the separate looped straps provide little vertical support for the back pad when the straps are not under tension. This makes it difficult for the patient to properly position the back pad as he is putting on the brace and tightening the straps. Lack of vertical support also allows the pad to slip downward out of its proper position whenever tension on the straps is temporarily relieved, as when the patient moves.
There is a known variation of the Hendricks strap which is a single piece strap of a woven material reeved through both slots of the back pad and having opposite ends of the strap attached to the left and right side pads respectively. The means for attaching the strap to the side pads may also involve reeving the strap end through a slot in the side pad, folding the strap back on itself, and securing the strap end to the main portion of the strap with Velcro multiple hook and loop type fasteners. This type of strap provides more vertical support for the back pad than does the Hendricks strap because its one piece construction better resists buckling under the weight of the back bad. However, because this type strap is of constant width, the back pad can slip horizontally with respect to the strap, thereby moving out of its proper position.
It would be an improvement to provide a strap for use with a back brace having a back pad which would provide vertical support for the back pad and would prevent horizontal movement of the back pad when it is being worn.